pdfviewer: more code comments + concat the pdf matrix with the existing matrix in canvas, instead of reseting it.
Review URL: https://codereview.chromium.org/27057003
git-svn-id: http://skia.googlecode.com/svn/trunk@11735 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/experimental/PdfViewer/SkTrackDevice.h b/experimental/PdfViewer/SkTrackDevice.h
index 20f9e68..6018fcd 100644
--- a/experimental/PdfViewer/SkTrackDevice.h
+++ b/experimental/PdfViewer/SkTrackDevice.h
@@ -16,6 +16,11 @@
* A Track Device is used to track that callstack of an operation that affected some pixels.
* It can be used with SampleApp to investigate bugs (CL not checked in yet).
*
+ * every drawFoo is implemented as such:
+ * before(); // - collects state of interesting pixels
+ * INHERITED::drawFoo(...);
+ * after(); // - checks if pixels of interest, and issue a breakpoint.
+ *
*/
class SkTrackDevice : public SkBitmapDevice {
public:
@@ -39,6 +44,8 @@
virtual ~SkTrackDevice() {}
+ // Install a tracker - we can reuse the tracker between multiple devices, and the state of the
+ // tracker is preserved - number and location of poinbts, ...
void installTracker(SkTracker* tracker) {
fTracker = tracker;
fTracker->newFrame();